More cppcheck warnings

ValenceHistogramDialog.cc

@@ -57,7 +57,7 @@ namespace {
 
 class ValenceHistogram : public ACG::Histogram {
 public:
-    ValenceHistogram(const std::vector<size_t> &bins)
+    explicit ValenceHistogram(const std::vector<size_t> &bins)
     {
         std::vector<size_t>::const_iterator nonzero_begin = bins.begin();
         for (; nonzero_begin != bins.end() && *nonzero_begin == 0;

infoBar.hh

@@ -61,7 +61,7 @@ class InfoBar : public QWidget, public Ui::InfoBar
   Q_OBJECT
 
   public:
-    InfoBar(QWidget *parent = 0);
+    explicit InfoBar(QWidget *parent = 0);
     
     void showCounts();
     void hideCounts();

infoDialog.hh

@@ -61,6 +61,6 @@ class InfoDialog : public QDialog, public Ui::InfoWidget
   Q_OBJECT
 
   public:
-    InfoDialog(QWidget *parent = 0);
+    explicit InfoDialog(QWidget *parent = 0);
 };